DefinitionNatural menopause occurs when the ovaries stop producing the hormones estrogen and progesterone and the menstrual cycle is absent for one year. The average woman in the U.S. goes through menopause at 51.4 years of age, with the range being roughly 45 to 55. Menopause before the age of 40 is said to be "premature". The term perimenopause refers to the 1-3 year period before menopause, when symptoms of hormonal fluctuation are present. Surgical menopause occurs with removal of the ovaries, with or without removal of the uterus (hysterectomy).
Signs and SymptomsIn the perimenopausal woman, menstrual periods generally become irregular and cycles gradually become longer. Periods may be associated with heavy bleeding and large clots before periods cease altogether. Hot flashes, flushing, and night sweats occur in over 90% of women. These symptoms become more frequent and intense as menopause approaches. Fatigue and emotional instability (crying spells, depression) as well as insomnia are also frequent complaints.
In the postmenopausal period, some women have increased or decreased sex drive due to estrogen loss. The lack of estrogen also causes thinning of pubic hair and vaginal tissue. There is decreased vaginal lubrication that can result in painful sexual intercourse. The vaginal acidity (pH) also changes, which can cause vaginal irritation, itching, or discharge. Breasts shrink and become less firm. The cervix, fallopian tubes, and uterine ligaments also shrink and weaken, resulting in decreased support of the uterus and bladder. This weakening can result in bladder incontinence, especially when a woman laughs or sneezes.
The long-term consequences of estrogen loss are still being studied and debated. Osteoporosis (thinning of the bones) occurs mostly in postmenopausal women, in part, because of the decrease in estrogen levels. The role of estrogen in heart disease is still unclear. Heart disease in women increases after menopause until the incidence becomes approximately equal to heart disease in men, at about 6-7 years after menopause. It is thought that estrogen has a protective effect on the heart, perhaps because it favorably affects cholesterol profile, or by a mechanism that is still unclear. Macular degeneration, a degenerative disease of the eye, may also be related to estrogen loss and results in visual problems. Estrogen is also thought to inhibit skin wrinkling, teeth problems, and even decrease the liklihood of colon cancer, although many of these findings have not been proven. Finally, estrogen loss may contribute to the development of Alzheimer’s disease, although these findings are also conflicting.
DiagnosisMenopause is diagnosed by an elevated follicle stimulating hormone (FSH) level. FSH is a brain hormone that stimulates release of estrogen and progesterone from the ovaries. When the levels of estrogen and progesterone decline at menopause, the FSH levels rise in an attempt to increase estrogen and progesterone. An FSH level greater than 40mIU/mL is considered menopausal.
TreatmentMenopausal signs and symptoms can often be treated with hormone replacement therapy (HRT). Estrogens (premarin, ethinyl estradiol, or estrace) can alleviate or improve hot flashes, vaginal dryness and irritation, and osteoporosis; they may also improve emotional instability and protect against heart disease, Alzheimer’s disease, colon cancer, skin changes, and vision problems. A women who has not had her uterus removed must take progesterone (medroxyprogesterone acetate, norethindrone) with the estrogen as estrogen administered alone increases the risk of uterine cancer by building up the lining of the uterus. Progesterone neutralizes this effect so that there is no increased risk of uterine cancer with combination HRT. A woman who has had a hysterectomy may take estrogen alone.
Estrogen and progesterone may be given in various ways. Some regimens result in resumption of the menstrual cycle, and some methods cause periods of irregular spotting for several months before all bleeding stops.
The risks associated with hormone replacement therapy include increased incidence of blood clots and perhaps gallbladder disease. HRT should generally not be used in women who have histories of blood clots or some liver diseases. Some studies suggest that the use of estrogen (with or without a progesterone) for more than 5-10 years increases the risk of breast cancer. Therefore, for patients with family- or personal histories of breast cancer, estrogens are either avoided or used with caution.
Recently, an estrogen-like medication has been released. Raloxifene (Evista) is useful for osteoporosis prevention and is thought to have the same benefits as estrogen on the heart and perhaps brain and colon. This medication, furthermore, actually decreases the risk of breast cancer. Unfortunately, it can exacerbate hot flashes and can cause vaginal dryness. Like estrogen, raloxifene is associated with an increased risk of blood clots. Raloxifene is sometimes used in women who have first been treated for a couple years with estrogen/progesterone combinations until hot flashes have ceased, especially if there is a family history of breast cancer. Raloxifene treatment does not result in resumption of the menstrual cycle and, therefore, is sometimes the preferred method for women who consider even temporary menstrual bleeding to be unacceptable after menopause.
Hormone replacement therapy has advantages and disadvantages. However, the advantages are usually perceived to be greater than the disadvantages for most women, and hormone replacement therapy continues to be recommended by most physicians who treat postmenopausal women. HRT, however, must be tailored to individual patient preferences.